1. Field of the Invention
The invention relates to a method of fabricating an integrated circuit, and more particularly to a surface treatment method for a bonding pad.
2. Description of Related Art
After an integrated circuit device has completed the fabrication process, it is often assembled into a package to be utilized on a printed circuit board as part of a larger circuit. In order to connect electrically the package with the fabricated devices, a metal bond is formed on the bonding pad of the device. The bonding pad must be clean since any small amount of contamination can cause a metal bond failure and reduce yields.
In a process of fabricating, an aluminum bonding pad, the passivation layer located on the bonding pad is etched by plasma containing fluorine to form an opening within the passivation layer, and the bonding pad is therefore exposed to form a metal bond. However, during the etching, the fluorine in the plasma makes corrosion by reacting with the surface of the aluminum bonding pad. The corrosion causes metal bond failures and reduces yields (e.g. metal won't properly adhere to the bonding pad).